An air-cleaning device provided to a motor is connected in air communication to an intake channel for leading outside air into an air-cleaning case and to an air-supply channel for leading air cleaned in the air-cleaning case to a motor (engine).
A well-known example of this type of air-cleaning device is disclosed in Japanese Patent Application Laid-Open Publication No. H09-236057, in which the configuration is such that the intake channel is extended to the interior of the air-cleaning case, sound-deadening performance is enhanced, and the intake noise when leading air into the air-cleaning case can be favorably reduced.
Some motors are used as electricity-generating units that are integrally assembled with electrical generators. Among these electricity-generating units are those that are used in cogeneration apparatuses (combined heat-and-power apparatuses) that make use of the waste heat of the motor.
These cogeneration apparatuses are provided adjacent to houses, and there is therefore a need for technology for further reducing the intake noise of the motor to come into practical use.